Lamadian Oilfield Research Articles

Optimization of surfactant-enhanced injection parameters in Lamadian oilfield

Abstract Optimizing injection fluid parameters is critical for the development of unconventional reservoirs since it is the principal strategy for increasing surfactant recovery in low-permeability reservoirs. This study used numerical simulation methods to objectively investigate the influencing variables under various injected surfactant values, based on the reservoir features of the target block. Additionally, it established the yield relationship corresponding to changes in reservoir pressure. Consequently, a correlation was established between the amount of injection, concentration of surfactant, distance between wells, extreme difference in permeability, and increase in pressure. This led to the determination of appropriate injection parameters for enhancing surfactant permeability. The study’s findings have practical implications for determining the appropriate injection scale of a reservoir surfactant system.

Numerical simulation of enhanced throughput of surfactant in Lamadian oilfield

Based on the actual data of Lamadian oilfield in terms of geological structure, reservoir fluid physical properties and production dynamics, a numerical simulation geological model of CMG STARS chemical flooding module is established, which is consistent with the static and dynamic characteristics of the oil reservoir. In order to study the effect of enhanced throughput of surfactants, based on the mechanism of enhanced throughput of surfactants, the numerical model was established by defining parameters such as oil-water interfacial tension at different concentrations, residual oil saturation, oil-water relative permeability curve, capillary pressure, isotonic point change and surfactant diffusion coefficient in the formation, etc. The numerical simulation of surfactant enhanced throughput was carried out to optimize the surfactant enhanced throughput parameters in Lamadian oilfield, and the sensitivity sequence of each injection and production parameter to the surfactant enhanced throughput and oil was determined. The final recommended injection and production parameters are surfactant injection amount (10000m3), injection concentration (0.5%) and brazing time (2d). It is predicted that the cumulative oil increase can reach 1310m3, the initial daily fluid production is controlled at 80m3/d, the daily oil production can be increased by 10m3/d, and the water cut can be reduced by 10%.

Study on the limit of ineffective cycle control in Lamadian Oilfield in the late period of ultra-high water cut

The ineffective circulation in Lamadian oilfield is mainly banded ineffective circulation and dendritic ineffective circulation, and the ratio of ineffective circulation to the total well production is mostly concentrated below 40%. Therefore, this paper first divides the levels of ineffective circulation and simulates the proportion of liquid production in different levels of ineffective circulation to get the limits of ineffective circulation management. The results showed that the invalidation index R < 0.2 was a fourth-grade invalidation cycle, 0.2≤R < 0.3 was a third-grade invalidation cycle, 0.3≤R < 0.4 was a second-grade invalidation cycle, and R≥0.4 was a first-grade invalidation cycle. The reduction of water injection in the planar heterogeneous layer will lead to the decrease of cumulative oil production, and the discrimination index R is small, and the reduction range is almost unchanged. When the discriminant index R is above 0.4, the reduction of cumulative oil production increases significantly.

Evaluation of the development effect of polydynamic drive in Class IIB oil reservoir of Lamadian Oilfield

With the continuous deepening of oilfield development, the target of oilfield development is gradually shifting towards reservoirs with poor physical properties, and polymer flooding can better utilize such reservoirs.The heterogeneity of Class II B oil layer in Lamadian Oilfield is severe, and polymer flooding takes effect later, with a small decrease in watercut.A study was conducted on the evaluation of polymer flooding development effectiveness for Class II B oil layers through reservoir numerical simulation . Research has shown that when the initial watercut is constant, a lower injection pressure can increase the utilization degree of remaining oil in the middle and high permeability layers of Class II B oil layers. With the increase of injection pressure, the response time is shortened, and the decrease in watercut is reduced; As the watercut increases, the injection pressure should gradually increase in order to improve the recovery of low permeability reservoirs;As the watercut increases, the injection pressure should gradually increase in order to improve the recovery of low permeability oil layers;At a watercut of 95% and injection pressure of 7MPa, a field experiment was conducted with a molecular weight polymer of 12 million , and the response time was 6 months. The cumulative oil increase was 14675m3, achieving good polymer flooding effect.

Optimization of frac imbibition process system in Lamadian oilfield

The most effective way to develop oil fields is hydraulic fracturing. During the development process, it is found that the shut-in time after fracturing has a great impact on crude oil production, and the analysis believes that imbibition is the main reason. Therefore, it is necessary to study the influence of hydraulic fracturing on the imbibition law of oil reservoir, give full play to the imbibition function, and improve the development effect of oil field. In this paper, the relationship between imbibition and post- fracturing shut-in time and imbibition rate and post-fracturing shut-in time is studied, and on this basis, the production system is optimized and the limit shut-in time is determined.

Study on delamination exploitation limit of high water cut injection well in late period

During the later phase of reservoir development, the efficiency of water injection in wells declines, necessitating careful consideration of water injection methods and parameters. This study focuses on the Daqing Lamadian oilfield and investigates the strategy for dividing the stratified water injection layer section. The research takes into account several characterisation characteristics related to the physical attributes of the formation. Additionally, it establishes the methodology for calculating the boundaries of fluid volume in stratified water injection, taking into account various factors such as well distances, layer thicknesses, oil saturation, and others. The findings indicate that the extent of recovery diminishes as the coefficient of variation of seepage resistance within the water injection layer section increases. The most effective approach for segmenting the layers is by utilizing the coefficient of variation of seepage resistance. This method allows for the determination of the boundaries of the injection volume for various layers. The injection water volumes for different layer groups in the Lamadian oilfield are as follows: 1000 m3/d for S I, 9100 m3/d for S II, 4600 m3/d for S III, 1100 m3/d for P I, 4100 m3/d for P II, 2500 m3/d for G I, and 100 m3/d for G II. The results offer technical validation for the selection of injection parameters for well groups during the later stages of high water cut.

Remaining oil potential and adjustment countermeasures in fault X well area of Lamadian Oilfield

The distribution characteristics of remaining oil in fault well area X of Lamadian oilfield are studied by numerical simulation, and adjustment countermeasures are formulated. Through the establishment of numerical model, the geological reserves and residual reserves of each small layer are analyzed, and the oil saturation distribution diagram output by the model is calculated, and the distribution characteristics of different types of remaining oil are summarized. The results are as follows :(1) the residual reserves are mainly distributed in the channel, accounting for 57.0 % of the total residual reserves, followed by the main sheet sand; (2) The remaining oil is mainly affected by imperfect injection-production relationship, fault occlusion and plane interference, accounting for 95 % of the total reserves of the type. Imperfect injection-production relationship accounted for 73.58 % of remaining oil types. The second is the enrichment of remaining oil from plane disturbance, accounting for 12.3 %. Residual oil of fault occlusion accounted for 9.16 %. The optimal well spacing was 200m, and the final recovery was 2.84 % higher than the original well pattern.

Preparation and Optimization of Modified Asphalt by Profile Control Parameters at Lamadian Oilfield

The Lamadian oilfield has entered the stage of strong water cut after natural energy development and conventional water flooding development. The use of asphalt binder for profile control can not only adjust the contradiction between layers, expand the swept volume, but also improve the oil displacement efficiency. The field test has achieved certain results. The main oil layer in the Lamadian oilfield has a strong oil layer thickness and serious vertical and plane heterogeneity. After years of water injection development and polymer injection development, most oilfields have entered a period of strong water cut. In the test, it is found that the effect of different well layers is very different, the effect is unstable, and the reason is unclear. Therefore, it is necessary to carry out research on the adaptability and parameter optimization of profile control of asphalt binder through laboratory experiments. In this paper, the asphalt binder provided on site are modified and the dispersion effect of modified asphalt binder is studied, and the concentration of suspending agent is optimized. The artificial cemented core structure and injection method are improved to solve the problem of aggregated asphalt binder on the end face during injection. The displacement profile control experiment was carried out with artificial cores, and the matching relationship between the injected particle size of the asphalt binder and the permeability was determined, and the optimal injection amount was optimized for cores with different permeabilities. The research results show that adding a KCl (potassium chloride solution) solution with a concentration of 2% as a dispersant can exert a better dispersing effect on the asphalt binder. Through the plugging rate experiments of three types of asphalt binder, the profile control effect is determined as the best when the particle size of the asphalt binder is 0.06–0.1 mm. According to the experimental results, the experimental research on the injection concentration and profile control radius of the profile control agent system was carried out. Finally, it was determined that the injection concentration of 3500 mg/L and the profile control radius of 1/3–1/2 of the well spacing were the optimal injection parameters. The field application of a profile control agent provides experimental basis.

Experimental study on constant pressure of polymer flooding in second-class reservoirs

At present, the second-class oil layer has become the main polymer flooding replacement layer in the Lamadian Oilfield. The second-class oil layer has low permeability, low connectivity and serious heterogeneity. The results of the polymer flooding laboratory experiments are quite different from the field flooding effect. Polysystem design provides better guidance. Based on theoretical and field data analysis, this paper adopts constant pressure injection method. After the experimental injection fluid is seepage through a 1.5m long core, the core flooding experiment is carried out, that is, the problem of excessive pressure rise in polymer flooding is controlled, so that the injection fluid is closer to the oil layer. state of the injected system. The constant pressure polymer flooding experiment was used to establish the matching relationship between the polymer system and oil layers with different permeability, which effectively guided the design of the on-site polymer injection system. At present, indoor polymer flooding core experiments generally adopt the constant speed mode, without controlling the injection pressure. However, due to the influence of permeability, connectivity and other factors, the injection pressure increases greatly, and the reservoir water absorption is difficult, which leads to a great difference between the experimental results and the field effect. In order to make the indoor core experiment closer to the actual field injection state and better guide the design of polymer flooding scheme, it is urgent to optimize and improve the experimental method.

Demonstration Zone of “Water Control and Efficiency Improvement” in Area 1 of Laxi Block Study on fine liquid splitting method

Lamadian Oilfield has entered the late stage of ultra-high water cut development, and the producing conditions of each sublayer are different. In order to know the producing conditions of each sublayer more clearly, it is necessary to count the reserves and output conditions of each sublayer. Therefore, it is necessary to finely divide the liquid and oil production of each sublayer of the production well. The former liquid splitting method only considered the formation influencing factors, that is, the splitting method of formation coefficient, which could not meet the differences of different water cut in each sublayer at present. Through the research of fine liquid splitting method, we can clearly understand the production of each oil well layer in the block, the production status and adjustment potential of each sub-layer, thus guiding the adjustment and tapping potential of block layering measures. It provides a theoretical basis for the later development of ultra-high water cut block.

Study on the applicability of sand control fracturing technology in Lamadian oilfield

At present, the proportion of water drive fractured wells is as high as 85.8%, and the proportion of repeated wells is as high as 47.7%. In view of this reality, the potential tapping objects are gradually transferred to isolated sand body, river channel edge and top of thick oil layer. Due to the limited fracture length ratio of conventional fracturing, the potential tapping effect is poor. Therefore, the sand body fracturing method is adopted for this section, that is, increasing the fracturing scale and improving the production degree of oil layer by increasing the fracture length ratio. According to the statistics of the effect of sand control fracturing well, combined with the sand body development characteristics, connectivity characteristics and injection production relationship, the influencing factors of sand control fracturing effect are analyzed, and the applicability of sand control fracturing technology in Lamadian oilfield is clarified.

Application analysis of isotope water absorption profile in ternary test of second class weak alkali

In the weak alkali ASP flooding test of Pu II 4 - 9 reservoir in the second area of north east block of lamadian oilfield, the original well pattern of strong alkali ASP test area was used for backward development of Pu II 4 ~ 9 reservoir. According to the analysis of isotope water absorption profile results, the production degree of blank water flooding reservoir was obviously higher than that of strong alkali ASP test at the same stage. In this paper, the principle of isotope water absorption profile reflecting the utilization degree is analyzed, and it is considered that poor water quality is the reason for the large difference of utilization degree in test areas, and the feasible methods to reduce this kind of influence are put forward, and the corrected utilization degree in test areas is given.

Discussion on Reasonable Well Spacing of Polymer Flooding in the Second Class Reservoir of Lamadian Oilfield

Lamadian Oilfield entered the development stage of polymer flooding in the second-class reservoir in 2006. At present, 8 blocks of well distribution schemes have been compiled and 6 blocks have been put into production by perforation. From the well spacing adopted in the polymer flooding development block of Class II reservoir and the polymer flooding test area of Sa iii 4-10 reservoir in La’nan Area 1, the injection-production well spacing is mainly 106 m ~ 212 m. According to the current development effect of each block, the well spacing of each set has certain inadaptability. Therefore, this paper, on the premise of guiding the preparation of well distribution plan in Area 2 of Middle East Block of La’nan, discusses the reasonable well spacing of polymer flooding in the second class reservoir from the aspects of control degree of polymer flooding, well pattern density, single well controlled reserves and so on. Combined with the actual situation of the implemented polymer flooding block, it is concluded that when the injection-production well spacing is 150m, it has about 80% polymer flooding control degree for the second-class reservoir, which can ensure reasonable well pattern density and single well controlled reserves, and obtain higher recovery ratio and economic benefits.

Application of well-seismic reservoir prediction technology in oilfield

This study mainly takes the thick oil layer in Lamadian Oilfield as an example. This oil layer is mainly developed in the area dominated by fluvial sediments, and the reservoir sand body space changes frequently. If we only rely on the traditional single well logging data, it is difficult to directly and effectively predict the changes of the whole sedimentary sand body, and the spatial configuration relationship between river boundary and other sedimentary microfacies can not be effectively predicted. In order to effectively improve the understanding of cross-well sand bodies, it is necessary to effectively combine well seismic with reservoir prediction technology, give full play to the advantage of high resolution of well seismic in the longitudinal direction, and predict its specific adaptability and application according to different situations, so as to better improve the prediction accuracy of reservoir sand bodies and provide important information data for the rational adjustment of cross-well encryption and the formulation of effective measures to tap potential. Based on this, this article deeply analyzes the application value of well-seismic combined reservoir prediction technology in oil fields.

Identification of architectural elements based on SVM with PCA: A case study of sandy braided river reservoir in the Lamadian Oilfield, Songliao Basin, NE China

To improve the oil recovery in the middle and late stages of oilfield development, it is very necessary to study the subsurface reservoir architecture. However, how to effectively improve the efficiency of architecture identification is also a big problem for the logging big data in dense well pattern area. In this study, we apply support vector machine (SVM), a supervised machine learning algorithm, and principal component analysis (PCA) data dimension reduction to three types of logging data (spontaneous potential (SP), gamma ray (GR), and acoustic (AC)) in order to automate the identification of braided river architectural elements on the PI2 braided river sand group of the Lamadian Oilfield in the north of Daqing Placanticline in the Songliao Basin, China. Manual qualitative identification shows that the architectural elements of the second sand group of the first member of Putaohua braided river reservoir (PI2) in the Lamadian area consist of mid-channel bars, braided channels, and floodplains. The presence of three types of sediments (medium-to fine-grain sand, fine-grain silty sand, and mudstone) indicates that changes occur in the water body energy within the PI2 braided river. The SVM algorithm development process includes determining the input and output variables, selecting the kernel functions, optimizing the parameters, training the algorithm with known samples, and testing the algorithm. With the twelve feature parameters (median, relative barycenter, variance, and the root of variational variance of SP, GR and AC data, respectively) as input variables and the braided river architecture categories as output variables, we use Gaussian radial basis function (RBF) and grid search to determine the optimal parameters values for penalty factor C and parameter gamma (γ). Without dimension reduction, the identification accuracy of the algorithm is 85.15%. To eliminate data redundancy, we used PCA to reduce the input data dimensionality. With dimension reduction, the identification accuracy of the algorithm increased by 6.93 percentage points to 92.08%. Because the logging response features are not distinctly different in the transition zone of mid-channel bar and braided channel, it is common for these two architectures to be misclassified. Even with this persistent misclassification, the error of our SVM algorithm identification process is only 7.92%, this method is robust enough to provide accurate results when applied to specific repetitive and complex geological big data problems.

Genetic analysis of remaining oil in thin and poor layers in Lamadian oilfield

Understanding the distribution of remaining oil and its genesis is the basic work of geological research. Lamadian oilfield has entered the late development stage of ultra-high water cut, the thick oil layer of water drive is decreasing gradually, and the thin and poor oil layer is becoming an important target of adjustment and tapping potential below 1.0m. In order to further improve the development effect of thin and poor reservoir, it is necessary to analyze the saturation field of the numerical model based on interpretation result, core analysis result of sealed coring well and water drive model. The remaining oil characteristics of thin and poor reservoir are studied by means of statistics, genetic analysis, dynamic analysis and static analysis.

Study on Technical Limits of Well Pattern Adjustment for the third type oillayer in middle part of Lamadian oilfield

After the Lamadian oilfield enters the development period of ultra-high water cut, the third type oil layer will be in the stage of water flooding development in the medium and long term in the future. By recombining oillayers and rebuilding the well network, it is possible to better control the difference of oil layers, slowing plane, inter-layer and intra-layer contradictions, improving the development effect of multi oillayers sandstone reservoir in extra-high water cut period. This paper uses the subdivision of water-driven oillayers, recombining oillayers, many datas of field test, comprehensive analysising and studying the third type oil layer (Gao I6 and below), providing technical support for the adjustment of the well pattern network of the third type of oillayer development in the future, and forming an operational development model for the subdivision of water-driven oillayers, the reconstruction of well pattern in the development stage in ultra-high water cut.

Qualitative interpretation method of water flooding in independent off surface reservoir of Lamadian Oilfield

With Lamadian Oilfield entering the late stage of ultra-high water cut, the number of thick layers in water drive is becoming less and less, so it is imperative to study the remaining oil in thin difference reservoir. For the thin difference reservoir, the independent off surface reservoir has naturally become an important research object [1]. It is necessary to study the waterflooding condition of the independent outer surface reservoirs to find out the producing law of the thin difference reservoirs at present. In this paper, we mainly use thewater washing data of independent outer surface reservoir and core data of sidewall of coring well to find the water flooding interpretation law of independent outer surface reservoir.This paper focuses on the analysis of the characteristics of the electric logging curve of the independent off surface reservoir after water flooding, and summarizes a set of qualitative interpretation methods suitable for the independent off surface reservoir of Lamadian oilfield. This method can improve the accuracy of waterflooded layer interpretation and meet the needs of remaining oil potential tapping in the later stage of ultra-high water cut.

Analysis on the effect of prolonged injection of oil layer in the Gao 2 Formation of La 8-182 well area in Lamadian Oilfield

At the end of 2012, the three types of oil layers completed the design of the polymer dosage. Since the water content did not rise and the concentration of the polymerization was low, the injection was prolonged from January of the 13th. The extension of the injection phase still has a strong injection capacity, and the water-bearing initial stage is slowly and slowly recovered. In this paper, the characteristics of water cuts in the extended injection phase of the test area are analyzed in combination with different water body water change laws and comprehensive adjustment methods, in order to optimize the three types of oil stratification. The design of the drive scheme provides a basis for accurately predicting the ultimate improvement of the recovery rate of the three types of oil layers.

Research on Deep Profile Control Technology of Water Flooding in Lamadian Oilfield

After Daqing Lamadian Oilfield entered the stage of development of ultra-high water cut, the ineffective circulation of various oil layers was serious, which restricted the development benefit of oilfields. To this end, the research on deep profile control of water flooding is carried out, and the combination of polymer microsphere flexible diverting agent and bulk expanded particle slug is used to exert a slower blocking speed of polymer microspheres, and a certain resistance is established in the deep pores of the reservoir. To provide the main slug with aggregating residence time; to exert the superior advantage of flexible steering agent deformation and adhesion ability, to form a dynamic path-distributing mechanism in the deep cavity of the reservoir; to play the advantage of faster blocking speed of the bulk-expanding particles, to prevent the main section The plug was flushed by subsequent water injection. Through the multi-segment combination indoor core experiment, it is shown that the front section is filled with microspheres, the main section is filled with flexible agent, and the post-segment is filled with expanded particles, which can well block the invalid circulation part, improve the displacement effect and improve The recovery rate can reach 3.12 percentage points. On October 16, 2013, Daqing Lamadian Oilfield carried out a deep liquid flow steering test study on the 9-injection and 16-hole water-flooding group. The comprehensive water content of the affected oil wells decreased by 7.8 percentage points, and the cumulative oil increase was 5,435 tons. The rate is 2.7 percentage points, and the input-output ratio is 1:4.0, which has achieved better mine results.